JP2002276863A - Tube for transferring fuel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tube for transferring fuel with flexibility which can be used for alcohol, gasoline or a mixed fuel of these. SOLUTION: The tube is superior in flexibility and permeation resistance to gasoline, alcohol, or a mixed fuel of these, it has a meta-xylene base including polyamide resin layer 2 with a thickness of <=0.3 mm and a polyolefinic resin layer 3, and it is formed by a simultaneous extrusion molding method. Polypropylene resin is used as polyolefinic resin 3. Polypropylene resin denatured by acid is used as the polyolefinic resin 3. Polypropylene resin denatured by maleic acid is used as polyolefine resin 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tube for transferring alcohol, gasoline, and a mixed fuel thereof (hereinafter, referred to as a fuel transfer tube).
It is about.

[0002]

2. Description of the Related Art As shown in FIG. 6, a tube for transferring an alcohol medium is composed of a polyamide 9 and a polyolefin layer 9 'on the inner side of the polyamide.

[0003] This is, for example, a medium for a brake system of an automobile (alcohol is added to prevent freezing).
In this case, the safety of the brake system is very excellent compared to the conventional polyamide tube due to the presence of the polyolefin layer having alcohol resistance and impermeability. It will be.

[0004] However, when a test (transfer test of gasoline and test of water permeation shown below) for transferring alcohol and gasoline alone by using the above-mentioned tube was performed, gasoline resistance was as shown below. It was confirmed that it was not good. Hereinafter, the method of this test is shown, and the test results are shown in Table 1.

In this test, the outer diameter was 8 mm, the inner diameter was 6 mm,
The thickness of the polyamide layer 9 is 0.9 mm, and the polyolefin layer 9 ′
A tube having a thickness of 0.1 mm was used. [Test Method] Gasoline Permeation Test Gasoline was sealed in a 200 mm tube (outer diameter 8 mm, inner diameter 6 mm), left in an oven at 50 ° C. for 5 days, and measured for weight loss. . Moisture Permeability Test A moisture adsorbent (molecular sieve) was sealed in a tube, left in a constant temperature and humidity chamber of 40 ° C. and 95% RH, and the weight increase of the moisture adsorbent was measured. . Flexibility test A 400 mm tube end was held, and the load required for 180 ° winding around a 100 mm radius semicircle was measured. . Test of length change by alcohol absorption A 200 mm tube was filled with methyl alcohol,
The length change after standing at 0 ° C. for 7 days was measured. 〔Test results〕

[0006]

[Table 1]

The symbols 表, ◎, Δ, and × in Table 1 above are shown in Table 2 below.

[0008]

[Table 2]

That is, from Tables 1 and 2, it can be seen that the above-mentioned tube has good alcohol resistance, but low gasoline impermeability.

[0010]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a flexible fuel transfer tube which can use any of alcohol, gasoline and a mixed fuel thereof.

[0011]

Means for Solving the Problems (Invention of Claim 1)
The fuel transfer tube of the present invention is a tube having excellent permeability resistance to gasoline, alcohol and a mixed fuel thereof, and excellent flexibility, and has a metaxylylene group-containing polyamide resin layer having a thickness of 0.3 mm or less, and a polyolefin. And a base resin layer, and is formed by a simultaneous extrusion molding method. (Invention of Claim 2) The fuel transfer tube of the present invention relates to the invention of Claim 1, wherein the polyolefin resin is a polypropylene resin. (The invention according to claim 3) The fuel transfer tube according to the present invention relates to the invention according to claim 1, wherein the polyolefin-based resin is a resin obtained by acid-modifying a polypropylene resin. (Invention according to claim 4) The fuel transfer tube according to the present invention relates to the invention according to claim 1, wherein the polyolefin resin is a polypropylene resin acid-modified with maleic acid.

The fuel transfer tube of the invention described above functions as follows.

The polyamide resin phase containing meta-xylylene group is
Even if it is 0.3 mm or less, gasoline permeation can be suppressed very small compared to the polyamide resin layer,
In addition, alcohol resistance is ensured by the polyolefin resin layer.

Since the metaxylylene group-containing polyamide resin layer has a thickness of 0.3 mm or less, flexibility, which is an essential function of the tube, can be secured.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the drawings showing embodiments. (Embodiment 1) As shown in FIG. 1, this embodiment is composed of two layers, the inside of which is a meta-xylylene group-containing polyamide resin layer 2 (hereinafter referred to as an MX nylon layer 2) and the outside. Is a polyolefin-based resin layer 3 (hereinafter, referred to as
PO layer 3). The MX nylon layer 2 is set to 0.2 mm, the PO layer 3 is set to 0.8 mm, and the entire tube is formed to have an outer diameter of 8 mm and an inner diameter of 6 mm. (Embodiment 2) This embodiment is composed of three layers as shown in FIG. 2, and the layers are composed of a PO layer 3, an MX nylon layer 2, and a polyamide resin layer 1 (hereinafter, referred to as an inner layer). , Nylon 12 layer 1). The PO layer 3 is 0.1 mm, the MX nylon layer 2
Is set to 0.1 mm, nylon 12 layer 1 is set to 0.8 mm,
As in the above embodiment, it is formed to have an outer diameter of 8 mm and an inner diameter of 6 mm. (Embodiment 3) This embodiment is composed of four layers, as shown in FIG. 3, from the inside to the outside, and comprises MX nylon layer 2, nylon 12 layer 1, PO layer 3, super The high molecular weight polyethylene layers 5 are laminated in this order. The MX nylon layer 2 is 0.1 mm, nylon 12
Layer 1 is set to 0.35 mm, PO layer 3 is set to 0.05 mm, ultra-high molecular weight polyethylene layer 5 is set to 0.5 mm, outer diameter 8 mm, inner diameter 6 mm
It is formed so that it becomes. (Embodiment 4) As shown in FIG. 4, this embodiment is composed of four layers. The layers are arranged from the inside to the outside, and the elastomer-containing nylon layer 6, the PO layer 3, the MX nylon layer 2, Nylon 12 layers 1 are laminated in this order. The elastomer-containing nylon layer 6 is 0.35 mm, PO
Layer 3 is 0.05 mm, MX nylon layer 2 is 0.1 mm, nylon 1
The two layers 1 are set to 0.5 mm and formed to have an outer diameter of 8 mm and an inner diameter of 6 mm. (Embodiment 5) This embodiment is composed of five layers as shown in FIG.
Nylon layer 2, PO layer 3, Elastomer-containing nylon 12
The layers are stacked in the order of layer 7. The elastomer-containing nylon layer 6 is 0.35 mm, the PO layer 3 is 0.05 mm, the MX nylon layer 2 is 0.1 mm, and the elastomer-containing nylon 12 layer 7 is 0.3 mm.
It is set to 45 mm and is formed to have an outer diameter of 8 mm and an inner diameter of 6 mm.

As the method of forming the fuel transfer tube of the above-described embodiments 1 to 5, any known method such as co-extrusion molding or extrusion coating can be used. By using co-extrusion molding using a base extruder and a multilayer tube die, an endless tube can be efficiently obtained.

Each resin can be molded into an arbitrary shape at a temperature not lower than the softening point and not higher than the decomposition point.
The molding is preferably performed at a temperature in the range of 50 to 320 ° C, particularly 190 to 280 ° C.

In the following, definitions of the main resins among the above-mentioned resins are shown, and the results obtained by the same method as the test method described in the column of the prior art are shown in Table 3. [Definition of Principal Resins] (Metaxylylene Group-Containing Polyamide Resin) In the present invention, the metaxylylene group-containing polyamide resin includes metaxylylenediamine or metaxylylenediamine and paraxylylenediamine of 30% or less of the total amount. Examples include a polymer containing at least 70 mol% of a structural unit formed from a mixed xylylenediamine and an α, ω-aliphatic dicarboxylic acid having 4 to 10 carbon atoms in a molecular chain.

Examples of these polymers include homopolymers such as polymetaxylylene adipamide, polymetaxylylene sebacamide, polymetaxylylene speramide, and the like, and metaxylylene / paraxylylene adipamide copolymer. , A copolymer such as meta-xylylene / para-xylylene pimeramide copolymer, a meta-xylylene / para-xylylene azeramid copolymer, and a component of these homopolymers or copolymers and hexamethylene diamine. Aliphatic diamines, cycloaliphatic diamines such as piperazine,
Aromatic diamines such as para-bis- (2-aminoethyl) benzene, aromatic dicarboxylic acids such as terephthalic acid, lactams such as ε-caprolactam, ω-aminocarboxylic acids such as γ-aminoheptanoic acid And copolymers of aromatic aminocarboxylic acids such as para-aminomethylbenzoic acid. In the above copolymer, paraxylylenediamine accounts for 30% or less of the total xylylenediamine, and the structural unit formed from xylylenediamine and aliphatic dicarboxylic acid accounts for at least 70% mol or more in the molecular chain. It is.

Since the metaxylylene group-containing polyamide resin itself is originally brittle in an amorphous state, its relative viscosity is usually 1.5.
It is necessary to be above, and it is preferably 2.0 to 4.0.

Further, these polymers may be, for example, nylon 4
・ 6, nylon 6, nylon 6.6, nylon 6.1
0, nylon 6,12, nylon 11, nylon 12,
A homopolymer or a copolymer such as nylon 12 may be contained.

To improve the flexibility, a soft rubber material such as styrene, butadiene rubber, chloroprene rubber, butyl rubber, nitrile rubber, ethylene propylene rubber, acrylic rubber, urethane rubber, chlorosulfone is added to the metaxylylene group-containing polyamide resin. 0 to 97% by weight, preferably 20 to 85% by weight of a thermoplastic elastomer such as a polyester elastomer, a polyamide elastomer, an olefin elastomer, a PVC-based elastomer, a urethane-based elastomer, a styrene-based elastomer, etc.
% By weight. Further, a relatively soft thermoplastic resin having an elastic modulus of 12000 kg / cm ² or less may be blended.

In the present invention, if necessary, various additives can be blended within a range not to impair the present invention. Examples of the additives include a colorant, an ultraviolet absorber, an antistatic agent, an antioxidant, a lubricant, a nucleating agent, a plasticizer, a flame retardant, an impact modifier, and an inorganic filler. (Polyamide resin) As the polyamide resin used in the present invention, a high-molecular-weight linear polyamide is used. The polyamide may be a homopolyamide, a copolyamide or a blend thereof.

Such polyamides include, for example, the following amide repeating units: —CO—R ¹ —NH— (1) or —CO—R ² —CONH—R ³ —NH (1) A homopolyamide having an amide repeating unit of (2) wherein each of R ¹ , R ² and R ³ represents a linear alkylene group;
Copolyamides or blends thereof can be mentioned. In consideration of gas barrier properties against oxygen, carbon dioxide, etc., the number of amide groups per 100 carbon atoms in the polyamide resin used in the present invention is 3 to 30, especially 4 to 4.
It is preferred to use a range of 25 homopolyamides, copolyamides or blends thereof. Specific examples of suitable homopolyamides include polycapramide (nylon 6), poly-ω-aminohepetanoic acid (nylon 7),
Poly-ω-aminononaic acid (nylon 9), polyundecaneamide (nylon 11), polylaurin lactam (nylon 12), polyethylene diamine adipamide (nylon 2,6), polytetramethylene adipamide (nylon 4,6 ), Polyhexamethylene adipamide (nylon 6,6) polyhexamethylene sebacamide (nylon 6,10) polyhexamethylene dodecamide (nylon 6,12) polyoctamethylene adipamide (nylon 8,6), Polydecamethylene adipamide (nylon 1
0,6), polydecamethylene sebacamide (nylon 1
0, 10) and polidodecamethylene dodecamide (nylon 12, 12). Examples of copolyamides suitable for use in the present invention include caprolactam / laurin lactam copolymer, caprolactam / hexamethylene diammonium adipate copolymer, laurin lactam / hexamethylene diammonium adipate copolymer, hexamethylene diamine Examples include ammonium adipate / hexamethylenediammonium sepacate copolymer, ethylenediammonium adipate / hexamethylenediammonium adipate copolymer, and caprolactam / hexamethylenediammonium adipate / hexamethylenediammonium sepacate copolymer.

In order to impart flexibility to these polyamides, a plastic or low-elastic elastomer component such as aromatic sulfonamides, P-hydroxybenzoic acid and esters, and lactams may be blended.

The elastomer component includes ionomer resin, modified polyolefin resin, polyetheramide resin, polyesteramide resin, polyetheresteramide resin, polyetherester resin, modified styrene thermoplastic elastomer, modified acrylic rubber, modified ethylene It is preferable to use one selected from elastomers having an elastic modulus of 3000 kgf / cm ² or less having good compatibility with polyamide resins such as propylene rubber, or a combination thereof. (Polyolefin resin) The polyolefin resin used in the present invention is generally a hydrocarbon resin, such as polyethylene, polybutadiene, polyisoprene, polyisobutylene, polybutylene, polymethylpentene,
Olefin polymers such as polypropylene, polyterpene resin, polybutene, ethylene-butadiene copolymer, and further ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1 decene, 1-hexadecene, 1- Α-olefin-based copolymers obtained by copolymerizing two or more kinds of eicosene, and also the above-mentioned olefin polymers and α-olefin-based copolymers with acrylic acid, methacrylic acid, α-methylacrylic acid, etc. Unsaturated dicarboxylic acids such as saturated monocarboxylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, nadic acid, and methylnadic acid; acid anhydrides, amides, and imides of the unsaturated carboxylic acids Graft copolymerization of derivatives such as water, anhydrides and esters Acid-modified olefin polymer or acid-modified α-olefin-based copolymer or a copolymer of these acid-modified α-olefin-based copolymer and a diene-based component. A mixture of more than one species can be used.

It is needless to say that the resin is not particularly limited to a thermoplastic resin, and that a crosslinked polyolefin resin such as a crosslinked polyethylene is also included. A suitable example is a water-crosslinked polyolefin, which is a polyolefin obtained by copolymerizing or grafting a compound containing a silyl group having a hydrolyzable organic group, which is reacted with water in the presence of a silanol condensation catalyst. There are polyolefins that can be crosslinked. 〔Test results〕

[0028]

[Table 3]

The symbols ◎, △, Δ, and × in Table 3 above represent Table 2
It is shown in FIG.

[0030]

The present invention has the following effects since it has the above-described configuration.

From Table 3 in the column of action, any of alcohol, gasoline, and a mixed fuel thereof can be used, and
A flexible fuel transfer tube could be provided.

[Brief description of the drawings]

FIG. 1 is a sectional perspective view of a fuel transfer tube according to a first embodiment of the present invention.

FIG. 2 is a sectional perspective view of a fuel transfer tube according to a second embodiment of the present invention.

FIG. 3 is a sectional perspective view of a fuel transfer tube according to a third embodiment of the present invention.

FIG. 4 is a sectional perspective view of a fuel transfer tube according to a fourth embodiment of the present invention.

FIG. 5 is a sectional perspective view of a fuel transfer tube according to a fifth embodiment of the present invention.

FIG. 6 is a sectional perspective view of a conventional tube.

[Explanation of symbols]

 2 Polyamide resin layer containing meta-xylylene group 3 Polyolefin resin layer

Claims (4)

[Claims] 1. A tube having excellent permeation resistance to gasoline, alcohol and a mixed fuel thereof, and excellent flexibility, comprising a metaxylylene group-containing polyamide resin layer having a thickness of 0.3 mm or less, and a polyolefin resin layer. And a fuel transfer tube formed by a coextrusion method. 2. The fuel transfer tube according to claim 1, wherein the polyolefin resin is a polypropylene resin. 3. The fuel transfer tube according to claim 1, wherein the polyolefin resin is a resin obtained by acid-modifying a polypropylene resin. 4. The fuel transfer tube according to claim 1, wherein the polyolefin resin is a polypropylene resin acid-modified with maleic acid.